| Summary: | Aeration leaching was used to obtain synthetic rutile from a reduced ilmenite. The reduced ilmenite, obtained from the carbothermic reduction of ilmenite concentrate in a rotary kiln at about 1100 °C, contained 62.88% TiO<sub>2</sub> and 28.93% Metallic iron. The particle size was about 200 μm and the size distribution was uniform. The effects of NH<sub>4</sub>Cl and HCl concentrations, stirring speed, and aeration leaching time on the extent of removal of metallic iron from the reduced ilmenite were studied at room temperature. The results revealed that aeration leaching is feasible at room temperature. When using the NH<sub>4</sub>Cl system, the metallic iron content was reduced to 1.98% in synthetic rutile, but the TiO<sub>2</sub> content only reached 69.16%. Higher NH<sub>4</sub>Cl concentration did not improve the leaching. Using 2% NH<sub>4</sub>Cl with 3% HCl, we were able to upgrade the synthetic rutile to 75%, with a metallic iron content as low as 0.14% and a total iron content of about 4%. Synthetic rutile could be upgraded to about 90% using HCl solution alone. HCl and NH<sub>4</sub>Cl are both effective on the aeration leaching process. However, within the scope of this experiment, hydrochloric acid is more efficient in aeration leaching.
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